RFR: 8342610: ZGC: Cleanup pre-touching code [v2]

[Stefan Karlsson]

> There's a few things that we'd like to cleanup around the pre-touching code.
> * Remove the dependency to ZPhysicalMemoryManager - cleans up the call site
> * Remove unimplemented function pretouch_view (and its friends)
> * Change type from zoffset for the iteration variable - multiple threads update it and it is not guaranteed to stay below the required ZAddressOffsetMax. I can trigger an assert here if I change the code to prime_cache in the higher address range instead of the lower and setting a max heap size that matches ZAddressOffsetMax.

Stefan Karlsson has updated the pull request incrementally with one additional commit since the last revision:

  Add explicit include of os.hpp

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Changes:
  - all: https://git.openjdk.org/jdk/pull/21600/files
  - new: https://git.openjdk.org/jdk/pull/21600/files/fdb58e36..2b77896c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=21600&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=21600&range=00-01

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/21600.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/21600/head:pull/21600

PR: https://git.openjdk.org/jdk/pull/21600